rust: Add rust_ffi_static vendor ramdisk Support

Similar to our vendor support, this adds support for linking rust static
libraries to vendor ramdisk cc modules.

A bug fix is also included where a restriction against setting rust_ffi
vendor-specific was not being enforced.

Bug: 179397942
Test: Example modules link, Soong tests pass.
Change-Id: I737cdf0c2f49ab349bcea2a0429e6298ebc1313e
diff --git a/cc/cc.go b/cc/cc.go
index df38499..7f59158 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -1544,7 +1544,7 @@
 		nameSuffix = productSuffix
 	} else {
 		vndkVersion = ctx.DeviceConfig().VndkVersion()
-		nameSuffix = vendorSuffix
+		nameSuffix = VendorSuffix
 	}
 	if vndkVersion == "current" {
 		vndkVersion = ctx.DeviceConfig().PlatformVndkVersion()
@@ -1591,11 +1591,11 @@
 	} else if _, ok := c.linker.(*vndkPrebuiltLibraryDecorator); ok {
 		// .vendor suffix is added for backward compatibility with VNDK snapshot whose names with
 		// such suffixes are already hard-coded in prebuilts/vndk/.../Android.bp.
-		c.Properties.SubName += vendorSuffix
+		c.Properties.SubName += VendorSuffix
 	} else if c.InRamdisk() && !c.OnlyInRamdisk() {
 		c.Properties.SubName += ramdiskSuffix
 	} else if c.InVendorRamdisk() && !c.OnlyInVendorRamdisk() {
-		c.Properties.SubName += vendorRamdiskSuffix
+		c.Properties.SubName += VendorRamdiskSuffix
 	} else if c.InRecovery() && !c.OnlyInRecovery() {
 		c.Properties.SubName += recoverySuffix
 	} else if c.IsSdkVariant() && (c.Properties.SdkAndPlatformVariantVisibleToMake || c.SplitPerApiLevel()) {
@@ -2927,7 +2927,7 @@
 	} else if ccDep.InRamdisk() && !ccDep.OnlyInRamdisk() {
 		return libName + ramdiskSuffix
 	} else if ccDep.InVendorRamdisk() && !ccDep.OnlyInVendorRamdisk() {
-		return libName + vendorRamdiskSuffix
+		return libName + VendorRamdiskSuffix
 	} else if ccDep.InRecovery() && !ccDep.OnlyInRecovery() {
 		return libName + recoverySuffix
 	} else if ccDep.Target().NativeBridge == android.NativeBridgeEnabled {